<!DOCTYPE html>
<!-- .html -->
<html>
	<head>
		<meta charset="utf-8">
		<title>外部的JS代码</title>
		<script src="js/demo.js" type="text/javascript" charset="utf-8"></script>
	</head>
	<body>
		<button type="button" onclick="testTxt()">点击</button>
	</body>
</html>
